/* * TI OMAP1 Real Time Clock interface for Linux * * Copyright (C) 2003 MontaVista Software, Inc. * Author: George G. Davis or * * Copyright (C) 2006 David Brownell (new RTC framework) * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation; either version * 2 of the License, or (at your option) any later version. */ #include #include #include #include #include #include #include #include #include #include #include /* The OMAP1 RTC is a year/month/day/hours/minutes/seconds BCD clock * with century-range alarm matching, driven by the 32kHz clock. * * The main user-visible ways it differs from PC RTCs are by omitting * "don't care" alarm fields and sub-second periodic IRQs, and having * an autoadjust mechanism to calibrate to the true oscillator rate. * * Board-specific wiring options include using split power mode with * RTC_OFF_NOFF used as the reset signal (so the RTC won't be reset), * and wiring RTC_WAKE_INT (so the RTC alarm can wake the system from * low power modes) for OMAP1 boards (OMAP-L138 has this built into * the SoC). See the BOARD-SPECIFIC CUSTOMIZATION comment. */ #define DRIVER_NAME "omap_rtc" #define OMAP_RTC_BASE 0xfffb4800 /* RTC registers */ #define OMAP_RTC_SECONDS_REG 0x00 #define OMAP_RTC_MINUTES_REG 0x04 #define OMAP_RTC_HOURS_REG 0x08 #define OMAP_RTC_DAYS_REG 0x0C #define OMAP_RTC_MONTHS_REG 0x10 #define OMAP_RTC_YEARS_REG 0x14 #define OMAP_RTC_WEEKS_REG 0x18 #define OMAP_RTC_ALARM_SECONDS_REG 0x20 #define OMAP_RTC_ALARM_MINUTES_REG 0x24 #define OMAP_RTC_ALARM_HOURS_REG 0x28 #define OMAP_RTC_ALARM_DAYS_REG 0x2c #define OMAP_RTC_ALARM_MONTHS_REG 0x30 #define OMAP_RTC_ALARM_YEARS_REG 0x34 #define OMAP_RTC_CTRL_REG 0x40 #define OMAP_RTC_STATUS_REG 0x44 #define OMAP_RTC_INTERRUPTS_REG 0x48 #define OMAP_RTC_COMP_LSB_REG 0x4c #define OMAP_RTC_COMP_MSB_REG 0x50 #define OMAP_RTC_OSC_REG 0x54 #define OMAP_RTC_ALARM2_SECONDS_REG 0x80 #define OMAP_RTC_ALARM2_MINUTES_REG 0x84 #define OMAP_RTC_ALARM2_HOURS_REG 0x88 #define OMAP_RTC_ALARM2_DAYS_REG 0x8c #define OMAP_RTC_ALARM2_MONTHS_REG 0x90 #define OMAP_RTC_ALARM2_YEARS_REG 0x94 #define OMAP_RTC_PMIC_REG 0x98 #define OMAP_RTC_IRQWAKEEN 0x7C /* OMAP_RTC_CTRL_REG bit fields: */ #define OMAP_RTC_CTRL_SPLIT (1<<7) #define OMAP_RTC_CTRL_DISABLE (1<<6) #define OMAP_RTC_CTRL_SET_32_COUNTER (1<<5) #define OMAP_RTC_CTRL_TEST (1<<4) #define OMAP_RTC_CTRL_MODE_12_24 (1<<3) #define OMAP_RTC_CTRL_AUTO_COMP (1<<2) #define OMAP_RTC_CTRL_ROUND_30S (1<<1) #define OMAP_RTC_CTRL_STOP (1<<0) /* OMAP_RTC_STATUS_REG bit fields: */ #define OMAP_RTC_STATUS_POWER_UP (1<<7) #define OMAP_RTC_STATUS_ALARM (1<<6) #define OMAP_RTC_STATUS_1D_EVENT (1<<5) #define OMAP_RTC_STATUS_1H_EVENT (1<<4) #define OMAP_RTC_STATUS_1M_EVENT (1<<3) #define OMAP_RTC_STATUS_1S_EVENT (1<<2) #define OMAP_RTC_STATUS_RUN (1<<1) #define OMAP_RTC_STATUS_BUSY (1<<0) /* OMAP_RTC_INTERRUPTS_REG bit fields: */ #define OMAP_RTC_INTERRUPTS_IT_ALARM2 (1<<4) #define OMAP_RTC_INTERRUPTS_IT_ALARM (1<<3) #define OMAP_RTC_INTERRUPTS_IT_TIMER (1<<2) /* OMAP_RTC_PMIC_REG bit fields: */ #define OMAP_RTC_PMIC_POWER_EN_EN (1<<16) #define SHUTDOWN_TIME_SEC 2 #define SECS_IN_MIN 60 #define WAIT_AFTER (SECS_IN_MIN - SHUTDOWN_TIME_SEC) #define WAIT_TIME_MS (SHUTDOWN_TIME_SEC * 1000) /* OMAP_RTC_IRQWAKEEN bit fields: */ #define OMAP_RTC_IRQWAKEEN_ALARM_WAKEEN (1<<1) /* * Few RTC IP revision has special WAKEEN Register to enable Wakeup * generation for event Alarm. */ #define OMAP_RTC_HAS_IRQWAKEEN 0x2 static void __iomem *rtc_base; #define rtc_read(addr) __raw_readb(rtc_base + (addr)) #define rtc_write(val, addr) __raw_writeb(val, rtc_base + (addr)) /* we rely on the rtc framework to handle locking (rtc->ops_lock), * so the only other requirement is that register accesses which * require BUSY to be clear are made with IRQs locally disabled */ static void rtc_wait_not_busy(void) { int count = 0; u8 status; /* BUSY may stay active for 1/32768 second (~30 usec) */ for (count = 0; count < 50; count++) { status = rtc_read(OMAP_RTC_STATUS_REG); if ((status & (u8)OMAP_RTC_STATUS_BUSY) == 0) break; udelay(1); } /* now we have ~15 usec to read/write various registers */ } static irqreturn_t rtc_irq(int irq, void *rtc) { unsigned long events = 0; u8 irq_data; irq_data = rtc_read(OMAP_RTC_STATUS_REG); /* alarm irq? */ if (irq_data & OMAP_RTC_STATUS_ALARM) { rtc_write(OMAP_RTC_STATUS_ALARM, OMAP_RTC_STATUS_REG); events |= RTC_IRQF | RTC_AF; } /* 1/sec periodic/update irq? */ if (irq_data & OMAP_RTC_STATUS_1S_EVENT) events |= RTC_IRQF | RTC_UF; rtc_update_irq(rtc, 1, events); return IRQ_HANDLED; } static int omap_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled) { u8 reg; local_irq_disable(); rtc_wait_not_busy(); reg = rtc_read(OMAP_RTC_INTERRUPTS_REG); if (enabled) reg |= OMAP_RTC_INTERRUPTS_IT_ALARM; else reg &= ~OMAP_RTC_INTERRUPTS_IT_ALARM; rtc_wait_not_busy(); rtc_write(reg, OMAP_RTC_INTERRUPTS_REG); local_irq_enable(); return 0; } /* this hardware doesn't support "don't care" alarm fields */ static int tm2bcd(struct rtc_time *tm) { if (rtc_valid_tm(tm) != 0) return -EINVAL; tm->tm_sec = bin2bcd(tm->tm_sec); tm->tm_min = bin2bcd(tm->tm_min); tm->tm_hour = bin2bcd(tm->tm_hour); tm->tm_mday = bin2bcd(tm->tm_mday); tm->tm_mon = bin2bcd(tm->tm_mon + 1); /* epoch == 1900 */ if (tm->tm_year < 100 || tm->tm_year > 199) return -EINVAL; tm->tm_year = bin2bcd(tm->tm_year - 100); return 0; } static void bcd2tm(struct rtc_time *tm) { tm->tm_sec = bcd2bin(tm->tm_sec); tm->tm_min = bcd2bin(tm->tm_min); tm->tm_hour = bcd2bin(tm->tm_hour); tm->tm_mday = bcd2bin(tm->tm_mday); tm->tm_mon = bcd2bin(tm->tm_mon) - 1; /* epoch == 1900 */ tm->tm_year = bcd2bin(tm->tm_year) + 100; } static int omap_rtc_read_time(struct device *dev, struct rtc_time *tm) { /* we don't report wday/yday/isdst ... */ local_irq_disable(); rtc_wait_not_busy(); tm->tm_sec = rtc_read(OMAP_RTC_SECONDS_REG); tm->tm_min = rtc_read(OMAP_RTC_MINUTES_REG); tm->tm_hour = rtc_read(OMAP_RTC_HOURS_REG); tm->tm_mday = rtc_read(OMAP_RTC_DAYS_REG); tm->tm_mon = rtc_read(OMAP_RTC_MONTHS_REG); tm->tm_year = rtc_read(OMAP_RTC_YEARS_REG); local_irq_enable(); bcd2tm(tm); return 0; } static int omap_rtc_set_time(struct device *dev, struct rtc_time *tm) { if (tm2bcd(tm) < 0) return -EINVAL; local_irq_disable(); rtc_wait_not_busy(); rtc_write(tm->tm_year, OMAP_RTC_YEARS_REG); rtc_write(tm->tm_mon, OMAP_RTC_MONTHS_REG); rtc_write(tm->tm_mday, OMAP_RTC_DAYS_REG); rtc_write(tm->tm_hour, OMAP_RTC_HOURS_REG); rtc_write(tm->tm_min, OMAP_RTC_MINUTES_REG); rtc_write(tm->tm_sec, OMAP_RTC_SECONDS_REG); local_irq_enable(); return 0; } static int omap_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm) { local_irq_disable(); rtc_wait_not_busy(); alm->time.tm_sec = rtc_read(OMAP_RTC_ALARM_SECONDS_REG); alm->time.tm_min = rtc_read(OMAP_RTC_ALARM_MINUTES_REG); alm->time.tm_hour = rtc_read(OMAP_RTC_ALARM_HOURS_REG); alm->time.tm_mday = rtc_read(OMAP_RTC_ALARM_DAYS_REG); alm->time.tm_mon = rtc_read(OMAP_RTC_ALARM_MONTHS_REG); alm->time.tm_year = rtc_read(OMAP_RTC_ALARM_YEARS_REG); local_irq_enable(); bcd2tm(&alm->time); alm->enabled = !!(rtc_read(OMAP_RTC_INTERRUPTS_REG) & OMAP_RTC_INTERRUPTS_IT_ALARM); return 0; } static int omap_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm) { u8 reg; if (tm2bcd(&alm->time) < 0) return -EINVAL; local_irq_disable(); rtc_wait_not_busy(); rtc_write(alm->time.tm_year, OMAP_RTC_ALARM_YEARS_REG); rtc_write(alm->time.tm_mon, OMAP_RTC_ALARM_MONTHS_REG); rtc_write(alm->time.tm_mday, OMAP_RTC_ALARM_DAYS_REG); rtc_write(alm->time.tm_hour, OMAP_RTC_ALARM_HOURS_REG); rtc_write(alm->time.tm_min, OMAP_RTC_ALARM_MINUTES_REG); rtc_write(alm->time.tm_sec, OMAP_RTC_ALARM_SECONDS_REG); reg = rtc_read(OMAP_RTC_INTERRUPTS_REG); if (alm->enabled) reg |= OMAP_RTC_INTERRUPTS_IT_ALARM; else reg &= ~OMAP_RTC_INTERRUPTS_IT_ALARM; rtc_write(reg, OMAP_RTC_INTERRUPTS_REG); local_irq_enable(); return 0; } /* * rtc_power_off: Set the pmic power off sequence. The RTC generates * pmic_pwr_enable control, which can be used to control an external * PMIC. */ static void rtc_power_off(void) { u32 val; struct rtc_time tm; /* Set PMIC power enable */ val = readl(rtc_base + OMAP_RTC_PMIC_REG); writel(val | OMAP_RTC_PMIC_POWER_EN_EN, rtc_base + OMAP_RTC_PMIC_REG); /* Wait few seconds instead of rollover */ do { omap_rtc_read_time(NULL, &tm); if (WAIT_AFTER <= tm.tm_sec) mdelay(WAIT_TIME_MS); } while (WAIT_AFTER <= tm.tm_sec); /* Add shutdown time to the current value */ tm.tm_sec += SHUTDOWN_TIME_SEC; if (tm2bcd(&tm) < 0) return; pr_info("System will go to power_off state in approx. %d secs\n", SHUTDOWN_TIME_SEC); /* Set the ALARM2 time */ rtc_write(tm.tm_sec, OMAP_RTC_ALARM2_SECONDS_REG); rtc_write(tm.tm_min, OMAP_RTC_ALARM2_MINUTES_REG); rtc_write(tm.tm_hour, OMAP_RTC_ALARM2_HOURS_REG); rtc_write(tm.tm_mday, OMAP_RTC_ALARM2_DAYS_REG); rtc_write(tm.tm_mon, OMAP_RTC_ALARM2_MONTHS_REG); rtc_write(tm.tm_year, OMAP_RTC_ALARM2_YEARS_REG); /* Enable alarm2 interrupt */ val = readl(rtc_base + OMAP_RTC_INTERRUPTS_REG); writel(val | OMAP_RTC_INTERRUPTS_IT_ALARM2, rtc_base + OMAP_RTC_INTERRUPTS_REG); /* Do not allow to execute any other task */ while (1); } static struct rtc_class_ops omap_rtc_ops = { .read_time = omap_rtc_read_time, .set_time = omap_rtc_set_time, .read_alarm = omap_rtc_read_alarm, .set_alarm = omap_rtc_set_alarm, .alarm_irq_enable = omap_rtc_alarm_irq_enable, }; static int omap_rtc_alarm; static int omap_rtc_timer; static struct platform_device_id omap_rtc_devtype[] = { { .name = DRIVER_NAME, }, { .name = "am33xx-rtc", .driver_data = OMAP_RTC_HAS_IRQWAKEEN, }, {}, }; MODULE_DEVICE_TABLE(platform, omap_rtc_devtype); static int __init omap_rtc_probe(struct platform_device *pdev) { struct omap_rtc_pdata *pdata = pdev->dev.platform_data; struct resource *res, *mem; struct rtc_device *rtc; u8 reg, new_ctrl; omap_rtc_timer = platform_get_irq(pdev, 0); if (omap_rtc_timer <= 0) { pr_debug("%s: no update irq?\n", pdev->name); return -ENOENT; } omap_rtc_alarm = platform_get_irq(pdev, 1); if (omap_rtc_alarm <= 0) { pr_debug("%s: no alarm irq?\n", pdev->name); return -ENOENT; } res = platform_get_resource(pdev, IORESOURCE_MEM, 0); if (!res) { pr_debug("%s: RTC resource data missing\n", pdev->name); return -ENOENT; } mem = request_mem_region(res->start, resource_size(res), pdev->name); if (!mem) { pr_debug("%s: RTC registers at %08x are not free\n", pdev->name, res->start); return -EBUSY; } rtc_base = ioremap(res->start, resource_size(res)); if (!rtc_base) { pr_debug("%s: RTC registers can't be mapped\n", pdev->name); goto fail; } /* Enable the clock/module so that we can access the registers */ pm_runtime_enable(&pdev->dev); pm_runtime_get_sync(&pdev->dev); if (pdata->wakeup_capable) device_init_wakeup(&pdev->dev, 1); rtc = rtc_device_register(pdev->name, &pdev->dev, &omap_rtc_ops, THIS_MODULE); if (IS_ERR(rtc)) { pr_debug("%s: can't register RTC device, err %ld\n", pdev->name, PTR_ERR(rtc)); goto fail0; } platform_set_drvdata(pdev, rtc); dev_set_drvdata(&rtc->dev, mem); /* RTC power off */ if (pdata && pdata->pm_off && !pm_power_off) pm_power_off = rtc_power_off; /* clear pending irqs, and set 1/second periodic, * which we'll use instead of update irqs */ rtc_write(0, OMAP_RTC_INTERRUPTS_REG); /* clear old status */ reg = rtc_read(OMAP_RTC_STATUS_REG); if (reg & (u8) OMAP_RTC_STATUS_POWER_UP) { pr_info("%s: RTC power up reset detected\n", pdev->name); rtc_write(OMAP_RTC_STATUS_POWER_UP, OMAP_RTC_STATUS_REG); } if (reg & (u8) OMAP_RTC_STATUS_ALARM) rtc_write(OMAP_RTC_STATUS_ALARM, OMAP_RTC_STATUS_REG); /* handle periodic and alarm irqs */ if (request_irq(omap_rtc_timer, rtc_irq, IRQF_DISABLED, dev_name(&rtc->dev), rtc)) { pr_debug("%s: RTC timer interrupt IRQ%d already claimed\n", pdev->name, omap_rtc_timer); goto fail1; } if ((omap_rtc_timer != omap_rtc_alarm) && (request_irq(omap_rtc_alarm, rtc_irq, IRQF_DISABLED, dev_name(&rtc->dev), rtc))) { pr_debug("%s: RTC alarm interrupt IRQ%d already claimed\n", pdev->name, omap_rtc_alarm); goto fail2; } /* On boards with split power, RTC_ON_NOFF won't reset the RTC */ reg = rtc_read(OMAP_RTC_CTRL_REG); if (reg & (u8) OMAP_RTC_CTRL_STOP) pr_info("%s: already running\n", pdev->name); /* force to 24 hour mode */ new_ctrl = reg & (OMAP_RTC_CTRL_SPLIT|OMAP_RTC_CTRL_AUTO_COMP); new_ctrl |= OMAP_RTC_CTRL_STOP; /* BOARD-SPECIFIC CUSTOMIZATION CAN GO HERE: * * - Device wake-up capability setting should come through chip * init logic. OMAP1 boards should initialize the "wakeup capable" * flag in the platform device if the board is wired right for * being woken up by RTC alarm. For OMAP-L138, this capability * is built into the SoC by the "Deep Sleep" capability. * * - Boards wired so RTC_ON_nOFF is used as the reset signal, * rather than nPWRON_RESET, should forcibly enable split * power mode. (Some chip errata report that RTC_CTRL_SPLIT * is write-only, and always reads as zero...) */ if (new_ctrl & (u8) OMAP_RTC_CTRL_SPLIT) pr_info("%s: split power mode\n", pdev->name); if (reg != new_ctrl) rtc_write(new_ctrl, OMAP_RTC_CTRL_REG); return 0; fail2: free_irq(omap_rtc_timer, rtc); fail1: rtc_device_unregister(rtc); fail0: pm_runtime_put_sync(&pdev->dev); pm_runtime_disable(&pdev->dev); iounmap(rtc_base); fail: release_mem_region(mem->start, resource_size(mem)); return -EIO; } static int __exit omap_rtc_remove(struct platform_device *pdev) { struct rtc_device *rtc = platform_get_drvdata(pdev); struct resource *mem = dev_get_drvdata(&rtc->dev); device_init_wakeup(&pdev->dev, 0); /* leave rtc running, but disable irqs */ rtc_write(0, OMAP_RTC_INTERRUPTS_REG); free_irq(omap_rtc_timer, rtc); if (omap_rtc_timer != omap_rtc_alarm) free_irq(omap_rtc_alarm, rtc); rtc_device_unregister(rtc); /* Disable the clock/module */ pm_runtime_put_sync(&pdev->dev); pm_runtime_disable(&pdev->dev); iounmap(rtc_base); release_mem_region(mem->start, resource_size(mem)); return 0; } #ifdef CONFIG_PM static u8 irqstat; static int omap_rtc_suspend(struct platform_device *pdev, pm_message_t state) { u8 irqwake_stat; const struct platform_device_id *id_entry = platform_get_device_id(pdev); irqstat = rtc_read(OMAP_RTC_INTERRUPTS_REG); /* FIXME the RTC alarm is not currently acting as a wakeup event * source, and in fact this enable() call is just saving a flag * that's never used... */ if (device_may_wakeup(&pdev->dev)) { enable_irq_wake(omap_rtc_alarm); if (id_entry->driver_data & OMAP_RTC_HAS_IRQWAKEEN) { irqwake_stat = rtc_read(OMAP_RTC_IRQWAKEEN); irqwake_stat |= OMAP_RTC_IRQWAKEEN_ALARM_WAKEEN; rtc_write(irqwake_stat, OMAP_RTC_IRQWAKEEN); } } else { rtc_write(0, OMAP_RTC_INTERRUPTS_REG); } /* Disable the clock/module */ pm_runtime_put_sync(&pdev->dev); return 0; } static int omap_rtc_resume(struct platform_device *pdev) { u8 irqwake_stat; const struct platform_device_id *id_entry = platform_get_device_id(pdev); /* Enable the clock/module so that we can access the registers */ pm_runtime_get_sync(&pdev->dev); if (device_may_wakeup(&pdev->dev)) { disable_irq_wake(omap_rtc_alarm); if (id_entry->driver_data & OMAP_RTC_HAS_IRQWAKEEN) { irqwake_stat = rtc_read(OMAP_RTC_IRQWAKEEN); irqwake_stat &= ~OMAP_RTC_IRQWAKEEN_ALARM_WAKEEN; rtc_write(irqwake_stat, OMAP_RTC_IRQWAKEEN); } } else { rtc_write(irqstat, OMAP_RTC_INTERRUPTS_REG); } return 0; } #else #define omap_rtc_suspend NULL #define omap_rtc_resume NULL #endif static void omap_rtc_shutdown(struct platform_device *pdev) { rtc_write(0, OMAP_RTC_INTERRUPTS_REG); } MODULE_ALIAS("platform:omap_rtc"); static struct platform_driver omap_rtc_driver = { .remove = __exit_p(omap_rtc_remove), .suspend = omap_rtc_suspend, .resume = omap_rtc_resume, .shutdown = omap_rtc_shutdown, .driver = { .name = DRIVER_NAME, .owner = THIS_MODULE, }, .id_table = omap_rtc_devtype, }; static int __init rtc_init(void) { return platform_driver_probe(&omap_rtc_driver, omap_rtc_probe); } module_init(rtc_init); static void __exit rtc_exit(void) { platform_driver_unregister(&omap_rtc_driver); } module_exit(rtc_exit); MODULE_AUTHOR("George G. Davis (and others)"); MODULE_LICENSE("GPL");